The present invention is directed to a receptacle, such as a pan, which is configured for nested stacking with other receptacles of the same or similar construction.
The advantages of nested stacking of receptacles for storage have long been recognized. Principal among those advantages is the reduced space occupied during storage, and a lesser susceptibility to damage of receptacles stored in a nested orientation. The employment of shoulders, flutes, corrugations, embossings, ridges, and other means of enlarging the perimeter of a receptacle to preclude jamming of adjacent receptacles during nested stacking is known. Several such configurations and structures are discussed in U.S. Pat. No. 5,035,327 to Denzin et al. for "Receptacle Adaptable for Nested Stacking", which is assigned to the assignee of the present application.
The Denzin et al. patent (U.S. Pat. No. 5,035,327) disclosed an improvement over the various structures and configurations discussed therein and provided a receptacle for nested stacking which presents a firm seat for nested stacking which accommodates dimensional differences among receptacles.
The present invention provides another solution to the shortcomings of prior art nested stacking receptacles. In particular, some prior art receptacles provide a circumferential ridge below the upper rim of the receptacle which establishes a slightly larger lateral area than the rim so that in a nested stacked orientation, there is established a line-to-line interference around the circumference of the receptacle between the ridge of an upper receptacle and the rim of a lower receptacle in the stack. The problem with such a line-to-line interference is that it provides opportunities for wobble and tilting because of differences in pan size (even though pans are made within established manufacturing tolerances, they may differ in size), deformation of pans occurring because of normal wear and tear, and other causes of imprecise alignment between adjacent pans. Such a wobble or tilting is not a major problem when only two pans or perhaps three pans are stacked together. However, when stacks of pans are nested several pans high, such wobbling or tilting can be a significant problem contributing to instability of the stacks.
The present invention provides an enhanced interference between adjacent pans in a nested stack which enhances a line-to-line interference provided by an existing stacking structure.